1. Field of the Invention
The present invention relates to a fluid dispersal device for widely dispersing fluid due to the self oscillation operation of a fluid jet.
2. Description of the Prior Art
The above described fluid dispersal device can disperse fluid by making use of the self oscillation of the fluid jet. So, such a movable member as to deflect the fluid is unnecessary.
Therefore, the above described fluid dispersal device can be made compact and the reliability thereof can be made high.
The above described fluid dispersal device can be widely applied to a window washer nozzle for a vehicle, a sprinkling nozzle for agriculture and industry, etc.
The above described fluid dispersal device conventionally has two types of the structures as shown in FIGS. 1 and 2.
In each of FIGS. 1 and 2, a housing 1 is provided with an inlet port 15 for supplying fluid under pressure to the interior of the housing 1, a nozzle 11 for jetting a fluid jet F, a fluid jet passage 12 and an outlet throat 13 for dispersing the fluid jet F out of the housing 1.
In the fluid dispersal device shown in FIG. 1 (hereinafter will be called "device A"), the fluid jet passage 12 is formed into a vortex chamber. One portion of the fluid jet F is made into a vortex flow within the vortex chamber and is returned toward the nozzle 11 to collide with the fluid jet F in a direction perpendicular thereto. This causes the fluid jet F to be deflected and oscillated.
The fluid dispersal device shown in FIG. 2 (hereinafter will be called "device B") is provided with a feedback passage 12'. One portion of the fluid jet F, which is attached to the wall of the fluid jet passage 12 is returned to the upstream end thereof by way of the feedback passage 12' to deflect the fluid jet F leftward or rightward.
The device A is simple in construction and can be easily produced since it is not provided with the above described feedback passage. However, in the device A, the returned vortex flow is diffused within a large vortex chamber so as to decrease the momentum to be exerted to the flow jet F at collision of the vortex flow therewith. In addition, the fluid jet F tends to maintain a straight flow. Therefore, it is difficult to obtain regular and uniform fluid dispersal over a wide range.
In order to overcome the above described problem of the device A, it has been tried to form a vortex of air within the vortex chamber and form a feedback passage between the formed air vortex and the side wall of the vortex chamber. In this case, there occur problems such that air bubbles are mixed with the fluid jet to make the dispersal density non-uniform.
The device B is free from the above described problems of the device A. However, the device B is comparatively complex in structure. In addition, the feedback passage 12' having a small diameter is liable to be clogged so as to make the operation of the fluid dispersal device unstable.